1. Field of the Invention
This invention relates generally to electromechanical translation devices, and more particularly relates to an apparatus for high resolution translation in one or two dimensions that is particularly useful, for example, in high resolution positioning instruments such as microscopes and optical instruments.
2. Description of Related Art
Various devices for precise linear or two dimensional motion, such as are useful in a scanning device, are known in the art. Electromechanical transducers such as piezoelectric ceramic laminates which expand upon being subjected to an electrical current have been used for controlling the position of machine tools. Piezoelectric ceramic laminates or stacks have also been coupled between parallel plates in such a fashion that two-dimensional motion of the control devices is possible. Stepwise fine positioning adjustment is also possible when piezoelectric stacks are combined for "walking" over a flat substrate. A channel walking device fitting in grooves in the channel for translation at cryogenic temperatures is known. A piezoelectric translating device for carrying and moving a flat plate in either one or two dimensions is also known.
It would be desirable to provide a positioning apparatus which travels within a stationary, rectilinear channel, to insure precise translational motion of the device. It would also be desirable to provide a high resolution two-dimensional positioning apparatus having support surfaces which have less total area than the total two-dimensional scanning area, in order to reduce the time and expense of precision machining of the substrate surfaces over which the positioning device travels. The present invention fulfills these needs.